1. Field of the Invention
The present invention relates to an apparatus and method for processing a data call in a private wireless high-speed data system and, more particularly, to an apparatus and method for processing a data call in a private wireless high-speed data system in which when there is a call connection to a private wireless high-seed data system network of which the security is required with a wireless terminal of a wireless high-speed data system (i.e., CDMA 1× EV-DO) scheme, the connection to the private EV-DO wireless network is allowed but the connection to a public EV-DO wireless network is blocked.
2. Description of the Related Art
Generally, a CDMA 1× EV-DO (code division multiple access 1× evolution data only (sometimes also called evolution data optimized), hereinafter, referred to as EV-DO) wireless network is a new packet wireless data transmission technology developed using a CDMA technology by QUALCOMM, which allows mega class high-speed data transmission. The EV-DO wireless network has a maximum transmission speed of 2.4 Mbps (megabits per second) in a forward direction and 307.2 Kbps in a backward direction, which is the same transmission speed as that in an asymmetric digital subscriber line (ADSL) scheme used in a wired network.
The advent of the EV-DO is because the 1× RTT system of an IMT-2000 MC (Multi-Carrier; synchronous), which has been developed to support both voice and data and has been tested for commercial use, has a limit in high-speed data transmission of 1.25 MHz (megahertz) bandwidth and also does not support data transmission of 144 Kbps or more in an IS-95 (Telecommunication Industry Association (TIA)/Electronic Industry Alliance (EIA) IS-95) scheme. That is, the EV-DO has appeared as a supplementary solution for the high-speed data transmission.
The EV-DO provides a connection to the data dedicated Internet over a data core network (DCN) in an existing IS-95 network. It can support the same data transmission speed as an existing one, even in the third generation (3G) network.
The EV-DO has an average forward transmission speed allowing high-speed data communication of several hundred kbps. Notwithstanding, the used radio frequency bandwidth is 1.25 MHz, which is the same as a mobile phone used in a current CDMA One.
Considering that a bandwidth of 5 MHz is required to provide 384 bps service in the IMT-2000, the system is regarded as a system of high frequency usage efficiency.
That is, the EV-DO has been designed in a manner suitable for data communication that is not affected by delay or instant when transfer data is burst data as in the Internet, realizing the high-speed transmission with a frequency bandwidth narrower than that of the IMT-2000.
Further, the EV-DO performs a function of automatically adjusting backward transmission speed at a base station side according to communication quality between a terminal and a base station. This function is realized by monitoring a signal from the terminal received at the base station per 1.67 m/s to recognize the communication quality and by adjusting data transmission priority and speed with the terminal.
It improves data communication quality by preferentially increasing transmission speed for a terminal in the vicinity of the base station where electric wave interference is less while by reducing communication speed for a terminal located far from the base station.
A typical wireless network is classified into a wireless public network and a wireless private network, which is used at groups, companies, or the like having a particular purpose. The wireless private network is configured to interwork with a particular wireless public network. On the other hand, in the above-described EV-DO wireless network, there exists only public EV-DO wireless network service provided by a mobile communication service provider while there is no private EV-DO wireless network service, unlike the typical wireless network.
Thus, it is a trend that methods are being developed which use a part of a public EV-DO wireless network as a private EV-DO wireless network. These methods allow one mobile terminal to be served by the private EV-DO wireless network in a particular region (private region) while by the public EV-DO wireless network in other regions.
One of these methods was proposed in the Korean patent application No. 10-2002-0054625 filed on Sep. 10, 2002 by the same applicant and entitled “Method and System for Using in Common a Public Network and a Private Network in a Wireless High-speed Data System”.
The proposed “method and system for using in common a public network and a private network in a wireless high-speed data system” will be simply discussed. Among methods for implementing a private EV-DO wireless network (private network) in an EV-DO network, the following methods have been suggested therein in configuring DLR (data location register) and AN_AAA (access network authentication accounting authorization) essential to the EV-DO configuration.
First, in the case of the DLR, there is a scheme of handling private network connection by allowing a direct connection to the public network DLR in order to configure the private network or by disposing a private dedicated DLR in the private network. Further, in the case of the AN_AAA, private authentication is handled by allowing a direct connection to the public network AN_AAA in order to handle private network connection authentication or by disposing a private dedicated AN_AAA in a private network, as in the DLR.                However, although such methods have advantages in their own way, the methods are not suitable for a region of which the security is required, namely, a private EV-DO wireless network as they allow a free connection from the private EV-DO wireless network to the public EV-DO wireless network. In particular, there is a problem with a direct connection scheme to the public EV-DO wireless network DLR in that building private EV-DO wireless network service is impossible because paging to the private EV-DO wireless network is not accomplished.        